1. Field of the Invention
The invention relates to an image formation apparatus.
2. Description of Related Art
A conventional image formation apparatus rotates a rotatably supported shaft in a toner cartridge that stores therein toner to agitate the toner stored in the toner cartridge. Japanese Patent Application Laid-open No. 2006-23537 discloses a technique by which the amount of toner that remains in the toner cartridge is detected by using a sensor to sense the rotational speed of the shaft.